Add -l N option to limit the load average.

This is similar to GNU make -l/--load-average option.  It limits the number
of job started if the load average exceed the given value.  It can be very
useful when running ninja on a continuous integration server where we want
to use parallelism as much as possible without overloading the server.

1 files changed, 4 insertions, 0 deletions

diff --git a/src/util.h b/src/util.h
index 9b4e745..399913e 100644
--- a/src/util.h
+++ b/src/util.h
@@ -68,6 +68,10 @@ const char* SpellcheckString(const string& text, ...);
 /// Removes all Ansi escape codes (http://www.termsys.demon.co.uk/vtansi.htm).
 string StripAnsiEscapeCodes(const string& in);
 
+/// @return the load average of the machine. A negative value is returned
+/// on error.
+double GetLoadAverage();
+
 #ifdef _MSC_VER
 #define snprintf _snprintf
 #define fileno _fileno